Master cylinder rebuild options
 

Does anyone know of a master cylinder rebuild kit? I took out the gold 78 this past weekend & was shocked to find the brake pedal going much closer to the floor than in the past. I found the rear reservoir was all but empty. Bled out the system & found zero leaks, or any evidence of a past leak. I am guessing the master has a super slow drip & it has been evaporating over the years. I honestly don't think I have looked at the brake fluid on this car in 10 years. :( I normally take it out at least once a year & put a few miles on it. This is the first time I have driven it it 2 years.

I am not big on replacing the master with a cheap $30 rebuilt or aftermarket. Would feel better if I can run a hone through the bore & replace the seals. Maybe its not the original anyway (like my seat belts ;) ) Does anyone know how to tell them apart? There is still a sticker on the side of it, but its unreadable. just a white square.

are your brake pads or shoe getting worn?

They are actually in really good shape. The rears are drum, so the rear resovoir really shouldn't get low on fluid like calipers do as the pistons move in. Backing plates behind the drums were dry & adjusters had the shoes out in a good location to the drums with no excessive movement. I am thinking it probably has been loosing just a small amount per year & I never noticed as it seems to evaporate. I looked again last night & everything is as dry as a bone.

While the rear was basically empty, the front was a little low as well. I have only put about 1500 miles on the car since I bought it. I used to put about 100 miles on it each summer, now over the past 6 or so years I am lucky if I go around the block once a year... :(

Food for thought: Exact same experience on our '78 not too long ago. Couldn't find the location of loss of fluid, thought it might be the master cylinder, or booster going bad w fluid migration into bellows, etc.

In our case - Same loss of rear fluid turned out to be rear brake cylinders that could only be found & seen when pulling rear wheels and brake drums...the 2nd time.

1st time removal nothing seemed wrong...or leaking :noidea:

Thats a really good thought & possibility. I'll take a look next spring. I already put the car back in its nest. I would imagine there will be some evidence by then.

Thanks for the idea!

Welcome & here's another http://www.brakeboosters.com/Master_...lve_Resto.html